Lubricant composition containing alkyl-mercaptoalkyl phosphites



Patented Aug. 3, 1954 I UNITED STATES PATENT OFFICE LUBRICANT COMPOSITION CONTAINING ALKYL-MERCAPTOALKYL PHOSPHITES Denham Harman, IOrinda, Califl, assignor to Shell Development Company, Emeryville, Calif., a corporation of Delaware No Drawing. Application November 29, 1951, Serial No. 259,015

17 Claims. (Cl. 252-334) This invention relates to lubricants having imformed by the removal of hydrogen atoms from proved stability and lubricating properties. saturated aliphatic hydrocarbons; X is a non- More particularly, this invention pertains to comoygen .chalkogen element, preferably sulfur and pounded lubricants having incorporated therein 1 is an integer of from 1 to 4.

an additive agent possessing outstanding Wide 5 Additive agents of this invention can be pretemperature anti-oxidant and extreme pressure pared by any suitable means such as the methods properties. employed in the copending application, Serial Various lubricants whether of natural and/or No. 381,561 filed July 13, 1948 and which has synthetic origin such as petroleum hydrocarbons, matured into U. S. Patent No. 2,587,616 of which fixed fats and oils and fractions thereof as Well this application is a continuation-in-part, are

as synthetic lubricants derived from olefinic polyparticularly preferred. mers, organic esters and the like, are generally Illustrative examples of additive agents of this affected by oxygen, air or under various oxidizinvention include:

ing conditions resulting in the formation of undesirable products and deleterious reactions which markedly decrease the useful life of such products or render them useless within a relatively short period of time for their intended purpose such as lubrication of engine parts. Additionally this phenomenon alters both the chemical and physical properties of both the additives and bas lubricant and in the case of the additives possessing extreme pressure properties, such properties are altered rapidly or dissipate, resulting at the best only in a temporary solution to extreme pressure lubrication.

One object of this invention is to impart extreme pressure properties to base lubricants and inhibit their oxidation over a wide temperature range. Another object of this invention is to prevent oxidation of base lubricants. Still another object of this invention is to produce an improved lubricant of outstanding stability and Bis 3 cyclohexylmercaptopropyl) phosphite extreme pressure properties by incorporating in Tris 3-c cloheximercaptopropyl) phosphite said base lviloriciant at, pargicular type of additive 3o 3 cyclopgmylmeicapto 2 methy1propy1 phosphite free from o jec iona 1e 0 ors. Other objects of th 1 r 1) this invention will be apparent from the follow- B158 cyclopentylmercapto 2 me y p opy B-amylmercaptopropyl phosphite Bis(3-amylmercaptopropyl) phosphite Tris(3-amylmercaptopropyl) phosphite 5-10entadecylmercaptopentyl phosphite Bis 5-pentadecylmercaptopentyl) phosphite Tris 5 -pentadecylmercaptopentyl) phosphite 3-amylmercapto-2methylp-ropyl phosphite Bis(3-amylmercapto-2-methylpropyl) phosphite Tris(3-amylmercapto-2-methylpropy1) phosphite 3-octylmercapto2-propylbutyl phosphite Bis(3-octylmercapto-2-propylbutyl) phosphite Tris(3-octylmercapto-2-propylbutyl) phosphite 3 (1,1,3 trimethylbutylmercapto) 2 methylpropyl phosphite BisES (1,1,3 trimethylbutylmercapto) 2- methylpropyl] phosphite Tris[3 (1,1,3 trimethylbutylmercapto) 2- methylpropyl] phosphite 3-cyclohexylmercaptopropyl phosphite ing description of this invention phosphite l l l r 2 h 1 r0 1 It has now been discovered that stable, excelgifg fig Openty me capto met y p py lent extreme pressure lubricants can be prepared by incorporating into a base lubricant minor amounts of a particular type of organo phosphites characterized by the presence of nonoxygen chalkogen atoms solely in the form of 3-amylselenylpropyl phosphite Bis 3-amylselenylpropyl) phosphite Tris(3-amylselenylpropyl) phosphite Trisl3 isobutylmercapto 2,3 dimethylbutyll phosphite non'oxy ether groups m replacmg hydrogen Octyl bis(3-amylmercaptopropyl) phosphite atoms of the hydroxy groups of phosphorous Benzyl bis (S-amylmercaptopropyl) phosphite acids. The preferred class of compounds comprises the alkyl-mercaptoalkyl phosphites, which Dthexyl 3octylmercapto'z'propylbutyl phosphite are aliphatic phosphites in which the aliphatic DIOYPIOheXYI 3 cyclohexylmercaptopropyl phos' radicals replacing the hydrogen atoms of the phlte hydroxyl groups of phosphorous acid, are of the -ethylhexyl 3-amyselenylpropyl phosphite general formula in which R and 3 amylmercaptopropyl dithio dicyclohexyl phosare polar or non-polar substituted non-aromatic Dhite hydrocarbyl radicals and preferably represent Chlorobenzyl bis(3-amylmercaptopropyl) phosmono and divalent 01-015 hydrocarbon radicals phite 3 Chlorophenyl bis(3-amylmercaptopropyl) phosphite Diallyl -pentadecylmercaptopentyl phosphite Dioleyl 3-octylmercapto-2-propyl phosphite Mono 3 octyl merctapto-2-propyl dithio octyl phosphite Tris(3-amyldimercaptopropyl) phosphite Poly phosphites can be used and include such compounds as:

C1CH2CH2OP( OH) OCH2CH2S- CHzCHaOP (OI-I) CHcCI-IzCl CH2=CHCH2OP OH) OCHaCI-Ic SCH2CH2OP (OH) CI-IzCI-I CHz Metal and nitrogen base salts of the acidic phosphorous esters of this invention can also be used as oil improving agents such as the Na, K, Li, Ca, Ba, Al, Zn and Pb as well as the amine salts of any of the above esters or mixtures thereof. Included among the preferred salts are:

Na, Ca and Pb salts of bis(3-arnylmercaptopropyl) phosphite Na, Ca, Zn and Al salts of cyclohexyl mercaptopropyl phosphite Di-Z-ethylhexyla-mine salt of bis(3-amy1mercaptopropyl) phosphite icyclohexylamine salt of cyclohexylmercaptopropyl phosphite Morpholine salt of 3-octylmercaptopropyl phosphite The non-oxygen chalkogen ether containing phosphites of this invention can be used to improve base lubricants, in concentrations varying from 0.001% to 20% and preferably from 0.1% to 5% by weight.

To illustrate the pronounced superiority of additives of this invention as anti-oxidants, the following lubricating compositions were prepared and evaluated by the Dornte Oxidation Stability Test as described in the National Petroleum News, September 1'7, 1941, pages R294-296, and in the High-Temperature Oxidation Apparatus of H. Diamond et al., which is fully described in the general papers presented before the Division of Petroleum Chemistry at the meeting of the American Chemical Society (September 18- 23, 1949, Atlantic City, New Jersey) on pages 31-45 of the reprints. Results of such tests are presented below.

[Baez Refined Mineral Lubricating Oil] Dornte Oxidation High Temperature Test (150 C; 150 Test, 260 0., 250 cc. (1112) cc. (mm) Cu crankcase Cu crankcase Cat. Get. Get. None 5 5 6.5 1.6% tri-octyl phosphite. 13 ll) 32 28 1.84% tris(3-amyl-mercaptopropyl) phcsphita 50 120 36 40 Co, etc. Organic bases include various nitrogen bases as primary, secondary, tertiary amines and quaternary ammonium compounds, e. g., benzyl trirnethyl ammonium hydroxide.

Examples of detergent-forming acids are the fatty acids of say, 10 to 30 carbon atoms, tall-oil acids, rosin acids, wool-fat acids, paraffin-wax acids (produced by oxidation of paraifin Wax), chlorinated fatty acids, aromatic hydroxy fatty acids, paraffin-wax benzoic acids, various alkyl salicyclic acids, phthalic acid monoesters, aromatic keto acids, aromatic ether acids, diphenols such as di-(alkylphenol) sulfides and disulfides,

, methylene bis-alkyl phenols; sulfonic acids such as may be produced by treatment of alkyl aryl hydrocarbons or high-boiling petroleum oils with sulfuric acid; sulfuric acid monoesters; phosphoric, arsonic and antimony acid monoand diesters, including the corresponding thiophosphoric and arsonic acids and the like.

Additional detergents are the alkaline earth phosphate di-esters, including the thiophosphate (ii-esters; the alkaline earth diphenolates, specifically, the calcium and barium salts of diphenol monoand poly-sulfides.

Non-metallic detergents include compounds such as the phosphatides (lecithin and cephalin) certain fatty oils such as rapeseed oils, Voltolized fatty or mineral oils and the like.

An excellent detergent for the present purpose is the calcium salt of oil-solule petroleum sulfonic acids. This may be present advantageously in the amount of about 0.025% to 0.2% sulfate ash. Also, alkaline metal salts of alkyl phenolaldehyde condensation products are excellent detergents.

Corrosion inhibitors or anti-rusting compounds may also be present, such as dicarboxylic acids of 16 or more carbon atoms; alkali metal and alkaline earth salts of sulfonic acids and fatty acids, organic compounds containing an acidic radical in close proximity to a nitrile, nitro, or nitroso group (e. g., alpha-cyanostearic acid), glycidyl phenyl ether, wax disulfide, etc.

Additional ingredients may comprise oil-soluble urea or thiourea derivatives, e. g., urethanes, allophanates, carbazides, carbazones, etc., polyisobutylene polymers, unsaturated polymerized esters of fatty acids and monohydric alcohols and other high-molecular-weight oil-soluble compounds.

Depending upon the additional additive used and conditions under which it is used, the amount of additive used may vary from 0.01 to 2% or higher. However, substantial; improvement is obtained by using amounts ranging from 0.1 to 0.5% in combination with the primary additive of this invention.

I claim as my invention:

1. An improved lubricant comprising a mineral lubricating oil base having incorporated therein from 0.01 to 5% by weight of tri(3-amylmercaptopropyl) phosphite.

2. An improved lubricant comprising a mineral lubricating oil base having incorporated therein from 0.01 to 5% by weight of bis(3-amylmercaptopropyl) phosphite.

3. An improved lubricant comprising a mineral lubricating oil base having incorporated therein from 0.01 to 5% by weight of tris(3-cyclohexylmercaptopropyl) phosphite.

4. An improved lubricant comprising a mineral lubricating oil base having incorporated therein from 0.01 to 5% by weight of 5-pentadecyl1nercaptopentyl phosphite.

5. An improved lubricant comprising a mineral lubricating oil base having incorporated therein from 0.01 to 5% by weight of 3-cyclophenylmercapto-2-methylpropyl phosphite.

6. An improved lubricant comprising a mineral oil base having incorporated therein a minor amount sufiicient to stabilize said oil base against oxidation deterioration of tris(3-amylmercapto propyl) phosphite. v

7. An improved lubricant comprising a mineral oil base having incorporated therein a minor amount sunicient to stabilize said oil base against oxidation deterioration of bis(3-amylmercapto propyl) phosphite.

8. An improved lubricant comprising a mineral oil base having incorporated therein a minor amount sufficient to stabilize said oil base against oxidation deterioration of tris(3-cyclohexylmercaptopropyl) phosphite.

9. An improved lubricant comprising a mineral oil base having incorporated therein a minor amount sufiicient to stabilize said oil base against oxidation deterioration of 5-pentadecyl mercaptopentyl phosphite.

10. An improved lubricant comprising a mineral oil base having incorporated therein a minor amount sufficient to stabilize said oil base against oxidation deterioration of 3-cyclopentylmercapto-2-methylpropyl phosphite.

11. An improved lubricant comprising a petroleum hydrocarbon base having incorporated therein in an amount suificient to stabilize said base against oxidation deterioration of an alkylmercaptoalkyl ester of phosphorous acid in which at least two hydrogen atoms of the acid are replaced by alkylmercaptoalkyl radicals.

12. An improved lubricant comprising a petroleum hydrocarbon base having incorporated therein in an amount sufiicient tostabilize said base against oxidation deterioration of an organic ester of phosphorous acid in which the organic radicals which replace hydrogen atoms from the hydroxyl groups of the acid have the formula RSR' in which R and R are saturated aliphatic hydrocarbon radicals, R and R containing from 1 to 15 carbon atoms.

13. An improved lubricant comprising a mineral oil base having incorporated therein in an amount sufficient to stabilize said base against oxidation deterioration of an organic ester of phosphorous acid in which the organic radicals which replace hydrogen atoms from the hydroxyl groups of the acid have the formula -RSR'- in which R and R are saturated aliphatic hydrocarbon radicals, R and R containing from 1 to 15 carbon atoms.

14. An improved lubricant comprising a petroleum hydrocarbon base having incorporated therein in an amount sufficient to stabilize said base against oxidation deterioration of an organic ester of phosphorous acid in which the organic radicals which replace hydrogen atoms from the hydroxyl groups of the acid have the formula RX-R'- in which R and R each are saturated aliphatic hydrocarbon radicals, R and R contain from 1 to 15 carbon atoms, X is an element selected from the group consisting of sulfur and selenium.

15. An improved lubricant comprising a liquid hydrocarbon lubricant base having incorporated therein in an amount suificient to stabilize said base against oxidation deterioration of an organic ester of phosphorous acid in which the organic radicals which replace hydrogen atoms from the hydroxyl groups of the acid have the formula RXR'- in which R and R each are saturated nonaromatic hydrocarbon radicals containing from 1 to 15 carbon atoms, X is an element selected from the group consisting of sulfur and selenium.

16. An improved lubricant comprising a mineral lubricating oil base, from about 0.01% to about 5%, by weight, of tris(3-amylmercapto propyl) phosphite, and from about 0.01 to about 2% of an oil-soluble calcium petroleum sulfonate.

17. An improved lubricant comprising a liquid hydrocarbon lubricant base, having incorporated therein, in an amount suflicient to stabilize said base against oxidation deterioration, an organic ester of phosphorous acid in which the organic radicals which replace hydrogen atoms of the hydroxyl groups of said acid have the formula -RXR' in which R and R each are saturated non-aromatic hydrocarbon radicals containing from 1 to 15 carbon atoms, X is an element selected from the group consisting of sulfur and selenium, and from about 0.01% to about 2% of an oil-soluble detergent.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,205,021 Schuette et al. June 18, 1940 2,241,244 Conary et a1. May 6, 1941 2,371,631 Lincoln et al Mar. 20, 1945 2,372,244 Adams et a1 Mar. 27, 1945 2,373,879 Dietrich Apr. 17, 1945 2,432,095 Frey -1 Dec. 9, 1947 2,587,616 Harman Mar. 4, 1952 2,614,988 Hook et a1. -a Oct. 21, 1952 

17. AN IMPROVED LUBRICANT COMPRISING A LIQUID HYDROCARBON LUBRICANT BASE, HAVING INCORPORATED THEREIN, IN AN AMOUNT SUFFICIENT TO STABLIZE SAID BASE AGAINST OXIDATION DETERIORATION, AN ORGANIC ESTR OF PHOSPHOROUS ACID IN WHICH THE ORGANIC RADICALS WHICH REPLACE HYDROGEN ATOMS OF THE HYDROXYL GROUPS OF SAID ACID HAVE THE FORMULA -R-X-R'' IN WHICH R AND R'' EACH ARE SATURATED NON-AROMATIC HYDROCARBON RADICALS CONTAINING FROM 1 TO 15 CARBON ATOMS, X IS AN ELEMENT SELECTED FROM THE GROUP CONSISTING OF SULFUR AND SELENIUM, AND FROM ABOUT 0.01% TO ABOUT 2% OF AN OIL-SOLUBLE DETERGENT. 